Many Dutch people sound American when they speak English because they learn English from a very young age, consume a huge amount of American media, and are encouraged to aim for a natural, near-native accent rather than a distinct Dutch one. The Netherlands also has a long tradition of English-language television, films, and music being shown in their original form with subtitles, not dubbed, which trains the ear early. As a result, their English often lands closer to a general American accent than the more recognizably foreign accents you might hear from German, French, or Slavic speakers.
Several practical factors explain this. First, English is a core school subject from around age 10, and many Dutch universities teach in English. Second, Dutch and English share Germanic roots, so sounds like th, r, and vowel contrasts are easier for Dutch speakers than for speakers of Romance or Slavic languages. Third, American pop culture dominates Dutch media, so learners imitate what they hear most. Finally, there is little social pressure to keep a Dutch accent in English; sounding American is often seen as a sign of fluency, not of losing identity.
That said, the effect is not universal. Some Dutch people have a clear Dutch accent, especially older speakers or those who learned English later. Others may sound more British if they studied in the UK or work with British colleagues. The American-sounding accent is also not identical to a native US accent; subtle differences in intonation, slang, and rhythm remain. So while it can be striking, it is a tendency, not a rule.
If you want to improve your own English or Dutch, focus on listening to a variety of accents, not just one. Watch Dutch television with Dutch subtitles to train your ear for Dutch sounds, and watch English-language content without subtitles to sharpen comprehension. Practice speaking aloud and record yourself to notice patterns. For structured help, consider a language course, a tutor, or a conversation group, and evaluate them by whether they offer regular speaking practice, feedback, and exposure to different accents. If your goal is Dutch fluency, prioritize daily listening and speaking over accent perfection. The key is consistent, varied input and honest feedback, not chasing a single accent.